The formation of oxides on the metallic surfaces to be soldered in solder reflow processes presents a problem because such oxides prevent the solder from "wetting" the surface to be soldered. Soldering inside a reducing atmosphere (e.g., Hydrogen-based or Formic acid) solves the oxide problem by reducing the oxide on the metallic surfaces.
Solder reflow equipment with reducing atmospheres is known and used in industry. However, Hydrogen-based reducing atmospheres require extensive safety control systems to operate (because of the physical properties of hydrogen), and commonly-used Formic Acid atmosphere systems operate best above 250 degrees Centigrade, which can damage most PWB materials and electronic components.
Thus, there is a need for solder reflow equipment that will lower the effective decomposition temperature of Formic Acid, allowing low temperature reflow of tin-based alloys for electronic assembly applications.